Optical design of monitoring network of groundwater quality in the Beijing Plain

This paper analyzed the history and current status of groundwater quality and monitoring in the Beijing Plain. The DRASTIC approach was used to assess the vulnerability of groundwater to pollution. The results show that the majority of the Beijing Plain is vulnerable to pollution. Groundwater vulnerability map, groundwater value ratings and groundwater protection areas were combined to create a groundwater protection urgency map. Major groundwater pollution sources were identified and mapped. The product of groundwater protection urgency and pollution sources ratings resulted in a groundwater pollution risk map. This map was used to locate the important sites for groundwater quality monitoring. The newly designed network consisted of 538 monitoring wells, of which 136 are multiple aquifer monitoring wells. 343 new monitoring wells are needed to install for monitoring groundwater pollution. Sampling frequency was determined according to the temporal changes in groundwater quality.